longest-common-prefix.js

// Write a function to find the longest common prefix string amongst an array of strings.
// If there is no common prefix, return an empty string "".

var longestCommonPrefix = function (strs) {
    if (strs.length === 0) return "";
    let prefix = strs[0];
    for (let i = 1; i < strs.length; i++) {
        while (strs[i].indexOf(prefix) !== 0) {
            prefix = prefix.slice(0, -1);
            if (prefix === "") return "";
        }
    }
    return prefix;
};